1. Field of the Invention
This invention relates to the preparation of alkyl-substituted phenols via reaction, in the presence of a catalytically active zeolite, of a phenol with an organic compound having an available alkyl group.
2. Description of the Prior Art
Several long-chain alkylphenols are known useful items of commerce. p-Nonylphenol, for instance, which is used primarily for surfactants, is currently produced in quantities of about 100 million pounds a year. Production of these compounds by conventional methods--for example, by the alkylation of phenol in the presence of conventional alkylation catalysts--is, however, somewhat problematic in that the reaction yields a broad spectrum of products. Isolation or enrichment of specific positional isomers is both difficult and expensive.
Traditionally, alkylation reactions are generally carried out at atmospheric pressure with the reactants in the liquid phase, utilizing catalysts such as sulfuric acid, boron trifluoride, aluminum chloride or strongly acidic ion exchange resins. Some zeolites, specifically REX and HY, have been reported in the scientific literature as catalyzing the reaction of 1-decyl alcohol with phenol at atmospheric pressure and 200.degree. C. The product of that reaction was predominantly an ortho/para mixture of decylphenols with side chain attachment largely at carbons #2 and #3 of the alkyl group.